Journal: iScience
Article Title: Lomitapide mesylate and lomitapide target ALDOA to inhibit growth and enhance gemcitabine efficacy in PDAC
doi: 10.1016/j.isci.2026.115316
Figure Lengend Snippet: Lomitapide mesylate and lomitapide inhibit PDAC independently of lipid metabolism, autophagy suppression, and P38 signaling (A) MTTP mRNA expression in human tissues, as retrieved from The Human Protein Atlas database. (B) MTTP mRNA expression in human cancer cell lines, as retrieved from The Human Protein Atlas database. (C) Basal MTTP expression in HepG2, BxPC3, and SW1990 cells. (D) Oil Red O staining of BxPC3 and SW1990 cells treated with 8 μM lomitapide mesylate, or 8 μM lomitapide, or an equivalent volume of DMSO (vehicle control) for 6 h. Scale bars, 200 μm (applies to all images in [D]). (E) LC3B-II and p62 protein expression in BxPC3 and SW1990 cells following the indicated treatments. (F) LC3 transformation assay in cells following treatment with 8 μM lomitapide mesylate, or 8 μM lomitapide, or an equivalent volume of DMSO (vehicle control), in combination with autophagy inhibitors. Cells were pre-treated with autophagy inhibitors (CQ, 20 μM; NH 4 Cl, 20 mM; or E64D [10 μg/mL] + pepstatin A [10 μg/mL]) for 1 h, followed by treatment with the aforementioned agents for 6 h. Protein extracts were then analyzed for LC3B expression. (G and H) Monitoring autophagic flux in PDAC cells using the mRFP-GFP-LC3 dual-labeling system. BxPC3 and SW1990 cell lines with lentivirus-mediated stable overexpression of stubRFP-sensGFP-LC3 were constructed to track autophagic flux. Following the indicated treatments, the distribution of LC3-positive puncta was visualized via laser confocal microscopy. Yellow fluorescent spots (merged mRFP and GFP signals) represent autophagosomes, while red fluorescent spots (mRFP-only signals, due to GFP quenching in the acidic environment of autolysosomes) indicate autolysosomes. Statistical analysis of the percentages of yellow and red puncta was performed to quantify changes in autophagic flux (H), n = 3. Scale bars, 20 μm (applies to all images in [G]). (I and J) Lomitapide mesylate and lomitapide were added 1 h after pretreatment with autophagy inhibitors or an activator, and cell viability was assessed 6 h thereafter. Autophagy inhibitors and activators used included WM, 5 μM; 3 MA, 5 mM; CQ, 20 μM; NH 4 Cl, 20 mM; E64D (10 μg/mL) + pepstatin A (10 μg/mL); or rapamycin, 10 μM ( n = 3). (K) BxPC3 and SW1990 cells were treated with the indicated treatments for 3 and 6 h, and the target proteins as well as their associated proteins were detected. (L) BxPC3 and SW1990 cells were pre-treated with SB202190 (10 μM) for 1 h, followed by the addition of the indicated treatments; cell viability was then assessed 6 h later ( n = 3). Data represent mean ± SD of three independent experiments. Statistical significance was determined using an unpaired two-tailed Student’s t test. ∗, p < 0.05, n.s., not significant.
Article Snippet: The human PDAC cell lines BxPC3 and SW1990, and the human hepatocellular carcinoma cell line HepG2, were obtained from ATCC (USA).
Techniques: Expressing, Staining, Control, Transformation Assay, Labeling, Over Expression, Construct, Confocal Microscopy, Two Tailed Test
ATCC is a verified supplier 
ATCC manufactures this product 
![Lomitapide mesylate and lomitapide inhibit PDAC independently of lipid metabolism, autophagy suppression, and P38 signaling (A) MTTP mRNA expression in human tissues, as retrieved from The Human Protein Atlas database. (B) MTTP mRNA expression in human cancer cell lines, as retrieved from The Human Protein Atlas database. (C) Basal MTTP expression in HepG2, BxPC3, and SW1990 cells. (D) Oil Red O staining of BxPC3 and SW1990 cells treated with 8 μM lomitapide mesylate, or 8 μM lomitapide, or an equivalent volume of DMSO (vehicle control) for 6 h. Scale bars, 200 μm (applies to all images in [D]). (E) LC3B-II and p62 protein expression in BxPC3 and SW1990 cells following the indicated treatments. (F) LC3 transformation assay in cells following treatment with 8 μM lomitapide mesylate, or 8 μM lomitapide, or an equivalent volume of DMSO (vehicle control), in combination with autophagy inhibitors. Cells were pre-treated with autophagy inhibitors (CQ, 20 μM; NH 4 Cl, 20 mM; or E64D [10 μg/mL] + pepstatin A [10 μg/mL]) for 1 h, followed by treatment with the aforementioned agents for 6 h. Protein extracts were then analyzed for LC3B expression. (G and H) Monitoring autophagic flux in PDAC cells using the mRFP-GFP-LC3 dual-labeling system. BxPC3 and SW1990 cell lines with lentivirus-mediated stable overexpression of stubRFP-sensGFP-LC3 were constructed to track autophagic flux. Following the indicated treatments, the distribution of LC3-positive puncta was visualized via laser confocal microscopy. Yellow fluorescent spots (merged mRFP and GFP signals) represent autophagosomes, while red fluorescent spots (mRFP-only signals, due to GFP quenching in the acidic environment of autolysosomes) indicate autolysosomes. Statistical analysis of the percentages of yellow and red puncta was performed to quantify changes in autophagic flux (H), n = 3. Scale bars, 20 μm (applies to all images in [G]). (I and J) Lomitapide mesylate and lomitapide were added 1 h after pretreatment with autophagy inhibitors or an activator, and cell viability was assessed 6 h thereafter. Autophagy inhibitors and activators used included WM, 5 μM; 3 MA, 5 mM; CQ, 20 μM; NH 4 Cl, 20 mM; E64D (10 μg/mL) + pepstatin A (10 μg/mL); or rapamycin, 10 μM ( n = 3). (K) BxPC3 and SW1990 cells were treated with the indicated treatments for 3 and 6 h, and the target proteins as well as their associated proteins were detected. (L) BxPC3 and SW1990 cells were pre-treated with SB202190 (10 μM) for 1 h, followed by the addition of the indicated treatments; cell viability was then assessed 6 h later ( n = 3). Data represent mean ± SD of three independent experiments. Statistical significance was determined using an unpaired two-tailed Student’s t test. ∗, p < 0.05, n.s., not significant.](https://pub-med-central-images-cdn.bioz.com/pub_med_central_ids_ending_with_1170/pmc13081170/pmc13081170__gr3.jpg)
![ALDOA, A potential target molecule of lomitapide mesylate and lomitapide (A) DARTS samples from lomitapide-treated SW1990 cells were subjected to Coomassie Blue staining and silver staining. The red box marks the gel areas of control and experimental samples that were analyzed by mass spectrometry. (B) COG function classification of identified proteins. The vertical axis represents the number of marked proteins, and the horizontal axis shows different COG functional categories. (C) GO functional enrichment analysis results. (D and E) Molecular docking (MOE 2019) analyzed binding interactions and sites between lomitapide and ALDOA. (E) Binding mode of lomitapide (purple sticks) with ALDOA (ribbon model), with key interacting residues (Lys-229, Lys-107, Lys-146, Tyr-363 and Arg-148) labeled. The protein structure of ALDOA was retrieved from the RCSB website, with PDB ID: 2ALD. (F) DARTS validation of ALDOA as a target of lomitapide in SW1990 cells: SW1990 cell lysates were treated with 100 μM lomitapide, and the stability of the ALDOA protein was assessed. Pronase digestion was performed for 10 and 20 min, respectively. The increased stability of ALDOA in lomitapide-treated lysates indicates its interaction with lomitapide. (G) DARTS assay demonstrated dose-dependent lomitapide-ALDOA binding. SW1990 lysates were incubated with lomitapide (various concentrations, 1 h) and then digested with pronase (10 min). (H) ALDOA expression in BxPC3/SW1990 cells following treatment with the indicated treatments. (I) ALDOA enzymatic activity in BxPC3/SW1990 cells following the indicated treatments. (J) Boxplot showing ALDOA expression levels in PDAC (analyzed via GEPIA). The red asterisk indicates a statistically significant difference between groups. (K) Kaplan-Meier curve for overall survival of PDAC patients (from TCGA dataset) stratified by ALDOA .TPM expression levels (high vs. low). (L) Overall survival of pancreatic cancer patients (from the KM Plotter database) stratified by ALDOA .TPM expression levels. (M and N) Immunohistochemical (IHC) staining of ALDOA in 90 paired PDAC tumor tissues (left) and paratumor tissues (right) (M). ALDOA-positive signals (brownish-yellow staining) were markedly enriched in tumor tissues compared with paratumor tissues. (N) shows the quantitative statistical analysis of ALDOA IHC staining intensity. Scale bars, 200 μm (applies to all images in [M]). (O) ALDOA expression and survival in 90 paired PDAC patients. (P and Q) OCR in BxPC3/SW1990 cells following the indicated treatments for 6 h via Seahorse XF analyzer. (R and S) ECAR in BxPC3/SW1990 cells following the indicated treatments via Seahorse XF analyzer. (T) ATP levels in BxPC3/SW1990 cells following the indicated treatments for 3 h or 6 h. (U) Comparison of ALDOA protein levels between control and shRNA-mediated ALDOA -knockdown BxPC3/SW1990 cells. (V) Colony formation assay of BxPC3 and SW1990 cells with ALDOA knockdown. (W) Cell viability of BxPC3/SW1990 cells ( ALDOA -KD/Con) following the indicated treatments for 48 h. Data represent mean ± SD of three independent experiments. Statistical significance was determined using an unpaired two-tailed Student’s t test. ∗, p < 0.05, ∗∗, p < 0.01, ∗∗∗, p < 0.001, ∗∗∗∗, p < 0.0001, n.s., not significant.](https://pub-med-central-images-cdn.bioz.com/pub_med_central_ids_ending_with_1170/pmc13081170/pmc13081170__gr4.jpg)
